426 Hippo

426 Hippo is a rather large main-belt asteroid. It was discovered by Auguste Charlois on August 25, 1897, in Nice. In the 22nd century, it will come closer than 6,000,000 km (0.04 AU) to the larger asteroids 65 Cybele and 511 Davida.^[2]

Orbital diagram of Hippo

426 Hippo

Modelled shape of Hippo from its lightcurve
Discovery
Discovered by	Auguste Charlois
Discovery date	25 August 1897
Designations
MPC designation	(426) Hippo
Pronunciation	/ˈhɪpoʊ/
Named after	Hippo Regius (Ἱππών Hippōn)
Alternative designations	1897 DH
Minor planet category	Main belt
Adjectives	Hipponian /hɪˈpoʊniən/[1]
Orbital characteristics[2]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc	112.19 yr (40977 d)
Aphelion	3.1893 AU (477.11 Gm)
Perihelion	2.5893 AU (387.35 Gm)
Semi-major axis	2.8893 AU (432.23 Gm)
Eccentricity	0.10384
Orbital period (sidereal)	4.91 yr (1793.8 d)
Mean anomaly	247.692°
Mean motion	0° 12m 2.484s / day
Inclination	19.4771°
Longitude of ascending node	311.419°
Argument of perihelion	222.319°
Proper orbital elements[3]
Proper semi-major axis	2.88928 AU
Proper eccentricity	0.179526
Proper inclination	20.3798°
Proper mean motion	73.2862 deg / yr
Proper orbital period	4.91225 yr (1794.199 d)
Precession of perihelion	32.8357 arcsec / yr
Precession of the ascending node	−59.8571 arcsec / yr
Physical characteristics
Dimensions	127.10±3.5 km[2]
Synodic rotation period	34.3 h (1.43 d)
Geometric albedo	0.0469±0.003[2]
Temperature	154-171 K
Spectral type	F
Absolute magnitude (H)	8.42[2]